Glycosphingolipids and gangliosides are of crucial importance as major membrane constituents of the cell, the majority of which are located at the outer leaflet of the plasma membrane. Recent investigations have demonstrated that glycosphingolipids on cell surfaces are one important way in which nature expresses its individuality.
For example, they serve as specific markers of the cells, particularly those forming blood group antigens, tumor cell markers, cell adhesion organ specific markers and growth regulators. They have been also implicated as receptors for toxins, hormones and interferons.
It has been shown that sphingosine and its derivatives have a prominent intracellular regulatory function.
However, the complete biological and pharmacological function of sphingosine still remains to be elucidated. Therefore, the development of an efficient stereoselective route to this material and its diastereomers on a multigram scale is still an important synthetic goal.
The important structural features of natural D-(+)-erythro-sphingosine include the absolute configuration at the two chiral centers of this aminodiol (2S, 3R) and the trans geometry of the double bond.
The process described in commonly owned U.S. Ser. No. 428,799 filed on even date herewith by Carl R. Illig and Alexander L. Weis and entitled "Total Synthesis of Chiral 2-Amino-1,3-Diols" is an efficient stereoselective route to the synthesis of 2-amino-1,3-diols, including sphingosine. It combines the advantages of less expense, exclusively chiral product, good overall yield and safety of reagents.
The oxazolidinone aldol adduct formed during this process is the subject of the present invention and is useful for synthesizing 2-amino-1,3-diols.
To further understand the nature of this invention, a reaction scheme is provided herein below. The oxazolidinone aldol adduct of the invention is produced in step A as shown. ##STR2##
Other compounds of the invention are made by conversion of the chloride to the azide as follows.